Referring to FIG. 1, an example of previous over-running clutches of this type is shown generally at 100. The clutch 100 includes an inner race 120, and outer race 112, a plurality of rolling elements 126 positioned therebetween, and an electromagnetic coil 144 adapted to generate a flux that causes the rolling elements 126 to lock the inner race 120 and outer race 112 to one another, thereby locking the clutch 100. A portion 102 of the outer race 112 extends axially to provide support for a rotor 136 that envelopes and the electromagnetic coil 144 that is mounted on a housing.
Due to the large forces that the inner and outer races 120, 112 experience, the outer race 112 is typically made from steel. The portion 102 of the outer race 112 that extends axially to provide support for the rotor 136 adds more steel to the clutch 100, thereby making the clutch 100 heavier. Further, steel is generally magnetically conductive. Using the portion 102 of the steel outer race 112 to support the rotor 136 creates the possibility that the flux generated by the electromagnetic coil 144 will leak or short-circuit through the outer race 112, thereby degrading or impeding the performance of the clutch 100.
Therefore, there is a need for an electromagnetic clutch assembly that supports the rotor and electromagnetic coil while allowing the clutch assembly to be lighter and reducing the chance that the electromagnetic flux will leak or short-circuit through the outer race.